Want to give your MightyOhm Geiger Counter Kit a little more sparkle?

Replace the ordinary indicator that comes with the kit with something special – a superbright LED!

Here’s how:

Step 1: Order some really bright LEDs

Superbright LEDs are available from most common electronics distributors, such as Jameco, Digikey, Mouser, etc. But instead of spending hours trying to find the LED you want in a catalog, I highly recommend ordering your LEDs from Evil Mad Science. EMSL sells curiously bright LEDs organized by color. I recommend their “5mm, Clear lens” LEDs in red, green, or blue.

You’ll also need a new dropping resistor R11 to go along with your LED choice. Some values of R11 for various LED colors are given below. If you see “0 Ohms” listed, you can either use an actual zero ohm resistor (yes, they exist), or a short piece of wire. Resistors are available anywhere electronic components are sold – I recommend a quick trip to Radio Shack. You might have to buy an assortment of resistors to get the value you want, but that’s not so bad – having lots of resistors around is always a good thing!

Here are some suggested resistor values to go along with various super and ultra-bright LEDs:

Step 2: Desolder the existing LED (LED1) and resistor R11

Desolder the LED and resistor R11. To do this, you’ll need desoldering braid (available at any electronics store), and maybe a desoldering pump/solder-sucker. If you have a fancy desoldering tool you should probably use it, it will make your life much easier.

Make sure to switch off and remove the AA batteries from your kit before you start removing components.

You can desolder the LED by heating the legs with your soldering iron and pulling on the LED gently with a pair of needle-nose pliers in a back-and-forth motion. Or, clip the leads under the LED, heat each one with your soldering iron, and pull it out of the PCB. R11 can be removed in a similar fashion.

After you have removed the components, use the desoldering braid or solder-sucker to clean out the holes in the PCB. You want the holes to be completely free of solder so that you can insert the new LED and resistor.

Step 3: Solder in your new superbright LED and resistor

Simply insert the new resistor and LED into the holes in the PCB and solder the terminals. Make sure the flat spot on the side of the LED lines up with the silkscreen markings on the PCB. Also, the longer lead should go into the hole marked +. The resistor can go in either way.

Clip off the excess leads (watch your eyes), and you’re done.

Step 4: Behold your pimped geiger counter!

Place the AA batteries back into the battery holder, turn on the power switch, and behold your pimped geiger counter!

If you ever get tired of the ‘pimped out’ look, you can always change LED colors (mind the dropping resistor) or go back to the original standard red LED. Or maybe you can talk to these guys…

Disclaimer: This modification will no doubt reduce your battery life, and the blue LED in particular will decrease in brightness quickly as the batteries drain (3V is barely enough to light up an ultra-bright blue LED). You might also attract unwanted attention when you use the kit, particularly in a dark environment, but if more attention is what you want (isn’t this why you pimped it out in the first place?), hack away!

This is my nephew, Harrison, doing what he does best – being cute.

For his first birthday, Harrison’s Mom wanted to give him something really special.  Not just an ordinary toy for a one year old, but something strange and wonderful, tactile, interactive, unique.  Thus was born the idea of an “electric box”, an electronic contraption full of switches, lights, buttons, knobs, levers, and sounds.

An elite task force was assembled to create this special gift, codenamed “Harrison’s Box”.  The team consisted of Grandpa, the Woodworker, Jeff (alias mightyohm) the Engineer, and Kylie, the Project Manager.

Upon defining the project, we immediately jumped into phase one, Procrastination.  Deliverables were met, and as the birthday loomed closer, we eased into phase two, Git ‘er’ Done.

Supplies and materials were ordered, wood chips started flying, and soldering irons blazed.  A short time later, the front panel was realized:

Harrison’s box consists of (clockwise from the upper left):

• A buzzer (sound comes out the four holes)
• A group of red, yellow, and green LEDs that respond to button pushes below
• A panel meter (for looks!) from the junkbox
• A pair of robots with blinking red eyes (aka tradeshow schwag)
• A pong controller, scrounged at the Prototype This! garage sale on Treasure Island
• Three large, brightly-colored arcade-style pushbuttons and a large joystick
• A numeric keypad
• Some random buttons and switches

Almost all of the electronic components, including the arcade buttons and joystick, were sourced from All Electronics.  A few odds and ends came from my junkbox.

The wiring is point to point – zipties and hot glue keep all of the individual wires in place.  Here’s a shot of the wiring for the pushbuttons and the joystick.

The buzzer consists of the guts of a cheap bicycle buzzer and a single C cell battery to power it.  Some creative wiring allows a pushbutton elsewhere on the panel to control the buzzer.

I salvaged a few high brightness red LEDs from a surplus automotive taillight assembly I picked up at Weird Stuff a few years ago.  A 5 Watt power resistor I had in my junkbox limits the current to the LEDs to a bright but not blinding level.

The whole box (with the exception of the buzzer, as noted above) is powered by a pair of AA batteries.

Finally, the big day arrived, and it was time to present Harrison (and Mom) with his gift:

Initially the Box was met with some skepticism.  Perhaps Harrison was dwelling on the simple question: Toy or thermonuclear device?  Understandably, there were very cautious button pushes at first.

Moments later, knobs were being turned, switches switched, buttons pushed, and Harrison had learned how to use the joystick.  Look out Steve Wiebe!

The front panel mounts to a small stand that conceals and protects the wiring while also giving Harrison something to hold onto while operating the Box.

I’m happy to report that Harrison’s Box was a success.

Check out more pictures of the box on flickr.

Marcus at Interactive Matter made this awesome space invaders button, inspired by Alex Weber’s 64pixels project.  It uses almost entirely SMT components and an ATmega164P microcontroller.

The PCB layout is gorgeous!

Marcus provides schematics, source code, and some helpful notes about surface mount soldering. I really like to see SMT projects like these popping up, proving that with the right tools, through hole packaging is no longer a necessity for DIY!

Space Invaders Button | Interactive Matter.